Sound conditioners are known which camouflage undesirable noise in the environment by generating white noise or background sounds such as the sound of ocean surf, rain, a rain forest, or a heartbeat. These devices are stand-alone units and usually sit on a night stand or the like for use by individuals at night to aid sleep.
Other mechanisms for avoiding exposure to unwanted sounds include passive mechanisms such as ear plugs or ear covers with noise-absorbing qualities. Active noise cancellation techniques are also known, and involve the use of a microphone for receiving external sounds which are converted into an electrical signal, after which an opposing-phase signal is generated. This opposing-phase signal is then supplied to a speaker in a headset and serves to cancel at least some of the external sounds by destructive interference.